Clamping device for a machine tool

ABSTRACT

A clamping device for a machine tool includes at least three pivoting members and a drive member drivingly connected to the pivoting members. The clamping device works in such a way that the pivoting members clamp the workpiece to be processed, then the drive member rotates the pivoting members, and the workpiece is also rotated while being clamped between the pivoting members. The clamping device employs at least three pivoting members to clamp the workpiece, and the three pivoting members clamp the workpiece while rotating the same, which can reduce vibration and balance the workpiece. Therefore, the clamping device is capable of reducing vibration, reducing machining errors and improving processing quality.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to TW 104131542, filed on Sep. 24, 2015 with the Intellectual Property Office of the Republic of China, Taiwan, the entire specification of which is incorporated herein by reference.

BACKGROUND

Field of the Invention

The present invention relates to a machine tool, and more particularly to a clamping device for a machine tool.

Related Prior Art

Machine tools are usually used for precision machining of metal to produce metal parts of other machines. The machine tools are capable of performing forming, cutting and connecting by moving the workpiece and the tool with respect to each other.

Most of the machine tools are provided with a clamping device to clamp the workpiece to be processed. The clamping device can be a three-claw or four-claw chuck. As shown in FIG. 1, a conventional clamping device includes a body 40 and three claws 41 movably disposed on the body 40. The claws 41 define a clamping space 42 which can be adjusted by moving the claws 41 to fit different workpieces of different sizes.

When a machine tool, a grinding machine for instance, is in use, the claws 41 clamp the workpiece, then the body 40 rotates to rotate the workpiece, then the grinding machine uses a grinding wheel to grind the workpiece. However, the claws 41 clamp the workpiece with only a single clamping point, vibration and sliding will inevitably occur when the workpiece is clamped while rotating.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

SUMMARY

The present invention is aimed at providing a clamping device for a machine tool which is capable of reducing vibration, reducing machining errors and improving processing quality.

To achieve the above objective, a clamping device for a machine tool in accordance with the present invention, comprises:

a base including a stationary seat and a slide seat located toward and spaced a distance apart from the stationary seat, a direction extending from the stationary seat to the slide seat is defined as a radial direction, wherein the stationary seat is fixed, and the slide seat is movable along the radial direction;

at least three pivoting members being cylindrical members pivotally mounted on the base and used to clamp a workpiece to be processed, each of the pivoting members being provided with a shaft, so that the pivoting members are sleeved onto the shafts, the shafts being pivotally mounted on the base, at least one of the pivoting members being disposed on the slide seat and arranged in the perpendicular direction, and at least one of the pivoting members being disposed on the stationary seat; and

a drive member being drivingly connected to and rotating at least one of the pivoting members.

It can be learned from the above description that the clamping device for the machine tool of the present invention works in such a way that the pivoting members clamp the workpiece to be processed, then the drive member rotates the pivoting members, and the workpiece is also rotated while being clamped between the pivoting members. The clamping device for a machine tool of the present invention employs at least three pivoting members to clamp the workpiece, and the three pivoting members clamp the workpiece while rotating the same, which can reduce vibration and balance the workpiece. Therefore, the clamping device for the machine tool of the present invention is capable of reducing vibration, reducing machining errors and improving processing quality.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conventional three-claw clamping device for a machine tool;

FIG. 2 is a perspective view of a clamping device for a machine tool in accordance with a preferred embodiment of the present invention;

FIG. 3 is an operational view of the clamping device for a machine tool in accordance with the preferred embodiment of the present invention;

FIG. 4 is a front view of the clamping device for a machine tool in accordance with the preferred embodiment of the present invention;

FIG. 5 is an enlarged view of a part of the clamping device for a machine tool in accordance with the preferred embodiment of the present invention;

FIG. 6 is an enlarged view of a part of the clamping device for a machine tool in accordance with another preferred embodiment of the present invention; and

FIG. 7 is an enlarged view of a part of the clamping device for a machine tool in accordance with yet another preferred embodiment of the present invention.

DETAILED DESCRIPTION

The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.

Referring to FIGS. 2-7, a clamping device for a machine tool in accordance with a preferred embodiment of the present invention includes: a base 10, at least three pivoting members 20, and a drive member 30.

The base 10 includes a stationary seat 11 and a slide seat 12 located toward and spaced a distance apart from the stationary seat 11. A direction extending from the stationary seat 11 to the slide seat 12 is defined as a radial direction X. The stationary seat 11 is fixed, and the slide seat 12 is movable along the radial direction X. The stationary seat 11 includes a first end 111 and a second end 112, and a direction extending from the first end 111 to the second end 112 is defined as a perpendicular direction Y.

The at least three pivoting members 20 are cylindrical members pivotally mounted on the base 10 and used to clamp a workpiece S to be processed. The workpiece S has a center point S1 and is clamped between the pivoting members 20. At least one of the pivoting members 20 is mounted on the slide seat 12, and at least one of the pivoting members 20 is mounted on the stationary seat 11. In a first preferred embodiment, as shown in FIGS. 5 and 6, each of the pivoting members 20 is provided with a shaft 21 on which the pivoting member 20 can be sleeved. The shafts 21 are pivotally mounted on the base 10, and there are three shafts 21 in this embodiment. One of the shafts 21 is disposed on the slide seat 12, and the rest two shafts 21 are disposed on the stationary seat 11. Preferably, the two shafts 21 on the stationary seat 11 are arranged in the perpendicular direction Y. The shaft 21 on the slide seat 12 is aligned in the radial direction X with the center point S1 of the workpiece S. In a second preferred embodiment of the present invention, as shown in FIG. 7, there are four pivoting members 20, two pivoting members 20 are disposed on the slide seat 12 and arranged in the perpendicular direction Y, and another two pivoting members 20 are disposed on the stationary seat 11 and also arranged in the perpendicular direction Y.

The drive member 30 is drivingly connected to at least one of the pivoting members 20. In the first preferred embodiment, the drive member 30 is drivingly connected to and rotates the pivoting member 20 disposed on the slide seat 12.

The workpiece S to be processed is firstly placed between the pivoting members 20, then the slide seat 12 moves in the radial direction X toward the stationary seat 11 until the pivoting members 20 clamp the workpiece S, then the drive member 30 is turned on to rotate at least one of the pivoting members 20, so that the workpiece S and the rest pivoting members 20 will also be rotated simultaneously, and the workpiece S can be firmly clamped between the pivoting members 20 while rotating stably. Finally, a grinding wheel L is used to process the workpiece S.

It can be learned from the above description that the clamping device for the machine tool of the present invention works in such a way that the pivoting members 20 clamp the workpiece S to be processed, then the drive member 30 rotates the pivoting members 20, and the workpiece S is also rotated while being clamped between the pivoting members 20. The clamping device for a machine tool of the present invention employs at least three pivoting members 20 to clamp the workpiece S, and the three pivoting members 20 clamp the workpiece S while rotating the same, which can reduce vibration and balance the workpiece S. Therefore, the clamping device for the machine tool of the present invention is capable of reducing vibration, reducing machining errors and improving processing quality.

While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

What is claimed is:
 1. A clamping device for a machine tool, comprising: a base including a stationary seat and a slide seat located toward and spaced a distance apart from the stationary seat, a direction extending from the stationary seat to the slide seat is defined as a radial direction, wherein the stationary seat is fixed, and the slide seat is movable along the radial direction; at least three pivoting members being cylindrical members pivotally mounted on the base and used to clamp a workpiece to be processed, each of the pivoting members being provided with a shaft, so that the pivoting members are sleeved onto the shafts, the shafts being pivotally mounted on the base, at least one of the pivoting members being disposed on the slide seat and arranged in the perpendicular direction, and at least one of the pivoting members being disposed on the stationary seat; and a drive member being drivingly connected to and rotating at least one of the pivoting members.
 2. The clamping device as claimed in claim 1, wherein there three said pivoting members, one of the three shafts is disposed on the slide seat, and the rest two shafts are disposed on the stationary seat.
 3. The clamping device as claimed in claim 2, wherein the stationary seat includes a first end and a second end, a direction extending from the first end to the second end is defined as a perpendicular direction, and the two shafts on the stationary seat are arranged in the perpendicular direction.
 4. The clamping device as claimed in claim 2, wherein the workpiece has a center point, and the shaft on the slide seat is aligned in the radial direction with the center point of the workpiece.
 5. The clamping device as claimed in claim 1, wherein there are four said pivoting members, two of the four pivoting members are disposed on the slide seat and arranged in the perpendicular direction, and another two of the four pivoting members are disposed on the stationary seat.
 6. The clamping device as claimed in claim 5, wherein the stationary seat includes a first end and a second end, a direction extending from the first end to the second end is defined as a perpendicular direction, the two shafts on the stationary seat are arranged in the perpendicular direction, and the two shafts on the stationary seat are also arranged in the perpendicular direction.
 7. The clamping device as claimed in claim 1, wherein the drive member is drivingly connected to and rotates the pivoting member disposed on the slide seat. 